Process of calcining.



Patented Fab. 6; I900,

J. GODFREY 8|. H. J. HAYES.

PROCESS OF CALCINING.

(Apphcatmn filed my 9 1899) (No Modal.) 2 Shasta-Sheet l.

Patented Feb. 6, I900.

GODFREY &. H. J. HAYES.

v PROCESS OF GALCINING.

(Application filed May 9, 1899.)

2 Sheets-Sheet 2.

(H11 Mod'el.)

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NITED STATES ATENT Fries- JOSEPH GODFREY AND HENRY JOHN HAYES, OF SWVANSEA, ENGLAND, AS- SIGNORS TO THE GODFREY OALOINER, LIMITED, OF LONDON, ENGLAND.

PROCESS OF CALCINING.

SPECIFICATION forming part of Letters Patent No. 642,602, dated February 6, 1900.

Application filed May 9, 1899. Serial No.7l6,083. (N pecimens-7 To all whom it may concern:

Be it known that We, JOSEPH GODFREY, assayer, residing at WValter road, and HENRY JOHN HAYES, commercial agent, residing at 203 Eaton Crescent, Swansea, in the county of Glamorgan, England, subjects of the Queen of Great Britain, have invented a certain new and useful Process of Calcining, of which the following is a specification.

According to this invention the material to becalcined-such as lead ores, sulfid ores containing lead, zinc ores containing lead, and

other ores and materialsis alternately heated in a closed furnace and exposed to the air out of contact with the products of combustion, thus causing rapid calcination and preventing fusion and volatilization of metals to any appreciable extent, while the heat of the furnace is in no way interfered with. This process may be conveniently carried out in the novel form of furnace shown in the drawings and which forms the subject of another application filed by us January 3, 1899, Serial No. 7 00,960. This furnace has an annular rotating bed which is partly covered by a fixed roof and partly uncovered.

Figure 1 is a plan, and Fig. 2 a vertical section on the line A A, Fig. 1, of a furnace constructedaccordingtothisinvention. Fig. 3 is a part right-hand side elevation of Fig. 1. In this view the levers operating the parts are omitted. Fig. at is a local section, to a larger scale, on the line B B, Fig. 1.

a is the annular bed of the furnace, (preferably covered with fire-clay tiles or other refractory material,) free to revolve about a central column b and supported by a ring of balls 0 and rollers d. On the under side of the bed Ct there is a ring of teeth 6, driven by any suitable gearing f.

The roof g and side walls h of the furnace are fixed, being supported by the central column b and by columns j. It will be observed that air can pass freely beneath the furnace.

is are plows fixed on stems Z, carried by a fixed radial bar m.

n are other plows in the form of fiat vertical plates pivoted at one end to the bar m and at the other to a movable bar 0, operated by a lever 19, pivoted at q.

The roof g is in the form of a segment of a circle, being entirely cutaway above the plows, so that these are in the open air.

7' are radial walls extending from the central column b to the side walls h and up to the roof g. The spaces between the bottoms of the walls 1' and the rotating bed a can be more or less closed, according to the depth of material on the bed, by adjustable plates 5, which lie against the outer faces of the walls 1 and can be moved up and down by the levers i, pivoted at to.

4; is the fireplace, and w the flue by which the products of combustion are led away. The material to be calcined may be fed onto the bed a at the opening x in the roof between the walls 4" or through a hole y formed in the roof between the left-hand wall 1 and the fire I place 1;. When the plows n are set as shown in Fig. 1, the material is gradually carried to the circumference of the bed (L as the latter revolves and is discharged over its edge between the walls T; but if the plows n are set tangentially to the path of the bed the material is not discharged.

The apparatus is so organized that the material is first heated in a closed furnace and then exposed while being stirred or rabbled to the oxidizing efiects of the atmosphere in the open air out of contact with the products of combustion. These steps are repeated, so

that the material is alternately heated and oxidized, the oxidation taking place while the material is being stirred, and at this time sulfur is rapidly released.

Although the above-described furnace is exceedingly well adapted for carrying out this invention, we do not limit ourselves to its use.

We claim- 1. The herein-described process of calcining which consists in alternately heating the material to be calcined in a closed furnace and exposing it to the open air, out of contact with the products of combustion.

2. The herein-described process of calcining which consists in alternately heating the material to be calcined in a closed furnace of combustion.

JOSEPH GODFREY. HENRY JOHN HAYES.

Witnesses:

WILLIAM Cox, JOHN WILLIAM PAOKE.

IOO 

